import java.util.Arrays;
import java.util.Scanner;
/*class Stu{
    private String name;
    public int age = 20;


    public Stu(String name, int age) {
        this.name = name;
        this.age = age;
    }


}
public class Main {*/
/*    public static void main(String[] args) {
        int[]arr = {4,6,2,7,29,56,32,1};
        System.out.println(Arrays.toString(arr));
        System.out.println(Arrays.binarySearch(arr, 29));
        Arrays.sort(arr);
        System.out.println(Arrays.toString(arr));
        System.out.println(Arrays.binarySearch(arr, 29));
    }*/
/*public static void main(String[] args) {
    int[]arr = {4,6,2,7,29,56,32,1};
    int[] ret = Arrays.copyOfRange(arr, 6, 8);  //[6, 8)
    System.out.println(Arrays.toString(ret));
}*/


/*    public static void main(String[] args) {
        int[]arr = {4,6,2,7,29,56,32,1};
        int[] ret = Arrays.copyOfRange(arr, 6, 8);  //[6, 8)
        System.out.println(Arrays.toString(ret));
    }*/



/*    public static void main(String[] args) {
        Stu stu = new Stu("aaaa",19);
        System.out.println(stu);
    }


}*/


public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        while (scanner.hasNextLine()){
            String str = scanner.nextLine();
            String ret = func(str);
            System.out.println(ret);
        }
    }

    public static String func(String str){
        StringBuffer sb = new StringBuffer();
        int[] array = new int[127];

        for (int i = 0; i < str.length(); i++) {
            char ch = str.charAt(i);

            if (array[ch] == 0){
                sb.append(ch);
                array[ch] = 1;
            }
        }
        return sb.toString();
    }
}

